>> BTW, rewriting that 1G file would be normal speed, since >> the modified chunks have already been copied to the snapshot. > i'd think that, and you'd think that, but it is not the case. most of > my tests were done by rewriting the file 4x, and while the snap %used > (monitored with the 'lvs' command) doesn't keep going up, performance > stays the same. > i did similar tests and i saw that even though i was rewriting the file, it appeared that the ext3 layer was reallocating new blocks. the snapshot usage would increase to show 3x the number of blocks i had thought it should have touched, and then it seemed to stay stable. this is one of the problems with a block level (as opposed to file level) snapshot. _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
